In Situ Reinforcing: ZrO₂-Armored Hybrid Polyimide Separators for Advanced and Safe Lithium-Ion Batteries

Abstract

High-performance polymeric separators are crucial materials for advanced rechargeable lithium-ion batteries (LIBs). Generally, separators need simultaneously possess qualified flame retardancy, mechanical strength, wettability, and ion conductivity. Here, we report a series of zirconium dioxide (ZrO 2 )-armored polymeric separators to boost the comprehensive performance of a separator by in situ growing a ZrO 2 nanolayer on polyimide (PI) nanofibers. The ZrO 2 nanolayer can serve as a protective coating to reinforce the PI nanofibers membrane. The ZrO 2 -reinforced layer endows a hybrid membrane with the superior strength of 39.24 MPa, which is instructive for the development of functional hybrid nanofibers. Moreover, ZrO 2 -armored PI separators display preferable wettability, fire resistance, and low ion-transport resistance as compared to those of a Celgard-2400 separator. The flame retardance of a ZrO 2 -armored PI separator also enhances the security of LIB. Specifically, ZrO 2 -armored hybrid PI separators display superb battery capability (128.6 mAh g −1 @5C) in comparison to polyolefin microporous membrane (95.2 mAh g −1 @5C). Furthermore, the cell using the ZrO 2 -armored PI nanofiber membrane shows high cycling stability over 100 cycles at 1C. Thus, the present study provides a design thought for the preparation of advanced organic/inorganic hybrid separators for LIBs.

Metal Oxide Nanoparticles: An Effective Tool to Modify the Functional Properties of Thermally Stable Polyimide Films

“…In recent years, the PI-based nanocomposite materials filled with metal oxide (MO) nanoparticles such as CeO 2 , ZrO 2 , NiO, TiO 2 , etc. have been extensively studied owing to the superiority of their functional properties over those of the unfilled PIs [10][11][12][13]. MO nanoparticles are now considered to form the basis of the diversity of modern "smart" materials and devices due to the possibility of manipulating their physical and chemical properties by changing the synthesis conditions of the nanoparticles and thus varying their characteristics such as size, morphology, surface stoichiometry (in particular, the number of oxygen vacancies), etc.…”

A Nonflammable and Thermally Stable Polyethylene/Glass Fiber−Magnesium Hydroxide/Polyethylene Composite Separator with High Mechanical Strength and Electrolyte Retention to Enhance the Performance of Lithium‐Ion Batteries

“…Compared with the modified polyolefin separator, the composite separator of nanofibers and high-temperature-resistant materials has better thermal stability and electrolyte wettability. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Chen et al [34] prepared a polyvinylidene fluoride (PVDF)/ triphenyl phosphate (TPP)/ cellulose acetate (CA) nanofiber separator by electrostatic spinning, which had good thermal stability and flame-retardant performance. Dong et al [35] coated the polyimide (PI) fiber with TiO 2 to prepare a separator that could maintain structural stability at 300 C. Nevertheless, in general, the composite fiber separator has poor mechanical strength, and there are always cracks, deformations, and short circuits after a certain degree of tension.…”

“…Compared with the modified polyolefin separator, the composite separator of nanofibers and high‐temperature‐resistant materials has better thermal stability and electrolyte wettability. [ 15–33 ] Chen et al [ 34 ] prepared a polyvinylidene fluoride (PVDF)/ triphenyl phosphate (TPP)/ cellulose acetate (CA) nanofiber separator by electrostatic spinning, which had good thermal stability and flame‐retardant performance. Dong et al [ 35 ] coated the polyimide (PI) fiber with TiO 2 to prepare a separator that could maintain structural stability at 300 °C.…”

Zirconium dioxide@phosphazene for enhancing mechanical property, flame retardancy, and thermal property of polythiourethane composites

“…[18][19][20][21][22] Several strategies for introducing ZrO 2 into the polymer matrix have emerged; these include physical addition and in-situ polymerization. 19,[23][24][25][26] Compared with the latter, the former has the advantages of economy, simple operation and mild conditions, and has been widely adopted by numerous researchers. However, due to the deformation incompatibility and the shortcomings of ZrO 2 being easy to agglomerate, severe stress concentration and poor dispersibility could be easily induced in the polymer network structure, resulting in the degradation of polymer performance.…”

“…Zirconium dioxide (ZrO 2 ) inorganic nanoparticles have recently attracted increasing research attention due to their high molar refraction, heat resistance, superior mechanical strength and unique electronic structures 18–22 . Several strategies for introducing ZrO 2 into the polymer matrix have emerged; these include physical addition and in‐situ polymerization 19,23–26 . Compared with the latter, the former has the advantages of economy, simple operation and mild conditions, and has been widely adopted by numerous researchers.…”